One-Step Fabrication of Non-Fluorinated Transparent Super-Repellent Surfaces with Tunable Wettability Functioning in Both Air and Oil

In this paper, we have developed a one-step thermal treatment of polydimethylsiloxane (PDMS) liquid to create transparent super-repellent surface (TSS) and super-repellent powder. They are super-repellent toward water and ethylene glycol. During the one-step thermal treatment, PDMS soot is generated and deposited onto a glass slide (GS) surface to fabricate the TSS without fluorosilane modification. The facilely obtained TSS presented superhydrophobicity and self-cleaning property when immersed into very low surface tension oils such as petroleum ether, hexadecane, peanut oil, and dodecane. Interestingly, by controlling heating time and temperature, wettability of the treated GS surface and the remained white powder can be regulated. The mechanism of tunable wettability was revealed and analyzed by investigating the variations of surface morphology and chemical composition. More importantly, TSS was able to repel highly corrosive aqua regia and saturated NaOH solutions. TSS maintained excellent superhydrophobicity even after chemical and mechanical damages. This simple thermal deposition method was also applicable for other thermally stable substrates to achieve super-repellency, which are believed to find very promising applications.